What is HE/SREAT?

Hashimoto’s encephalopathy (“HE”) is a rare autoimmune disease in which an immune system malfunction disrupts processes within the brain and nervous system, causing a variety of cognitive, neurological and/or neuropsychiatric symptoms.

In the ensuing years, physicians around the globe have continued to encounter similar patients who present with a perplexing array of symptoms that may include seizures, cognitive impairment, movement disorders, speech disturbances, ataxia, sleep disorders, and sometimes psychosis. Some cases have resulted in coma and even death.

Between 1966 and 1999, although physicians continued to encounter such patients around the world there was little published scientific research regarding the disease responsible for their symptoms. A few physicians even posited that they were really suffering from a purely psychiatric problem such as conversion disorder. Fortunately, the number of research studies looking into this poorly understood condition has escalated rapidly since 2000.

In recent years, researchers studying Hashimoto’s encephalopathy have proposed a variety of different names for the disease, including Steroid Responsive Encephalopathy Associated with Thyroiditis (“SREAT”); Encephalopathy Associated with Autoimmune Thyroid Disease (“EAATD”); and Non-vasculitic Autoimmune Inflammatory Meningoencephalitis (“NAIM”). Others simply refer to HE using the more generic term Autoimmune Encephalopathy (“AE”), which includes an ever-growing number of autoimmune diseases characterized by cognitive impairment and disruptions to the central nervous system.

Most scientists believe the name “Hashimoto’s Encephalopathy” is ill-advised since the disease is not causally related to Hashimoto’s thyroiditis (“HT”), despite the fact that HT is usually present in patients with HE. It is this common correlation that originally led to creation of the term Hashimoto’s Encephalopathy.

Until scientists find common ground and settle on an accepted name, this website will use “HE” as a shorthand way of referring to Hashimoto’s Encephalopathy/Steroid Responsive Encephalopathy Associated with Thyroiditis (“HE/SREAT”).

HE is recognized as a rare disease by the U.S. National Institutes of Health’s Office of Rare Diseases Research, which refers to it as “Hashimoto’s encephalitis.”